It seems to be a fair bit going on with Poser 9 and the lighting / blue tints .... so I have gathered a few bits to see if things can be found to help ...
Mainly, there appears to be a combination of SSS settings and the lighting or render settings used that is creating this unwanted effect. For the most part, the blue tint can often happen with SSS when the skin has something immediately under it. So since the head has teeth, tongue, and eye geometry under it, the skin on the face renders a slight blue around those areas. This is one of the issues with Poser's SSS feature that they are working on and fixing soon we all hope.
A suggestion was that when rendering with SSS and raytracing enabled, turn the visibility completely OFF for the mouth and tongue (assuming the mouth is closed, of course.) Can't do anything about the eyes unless the eyes are closed in this same manner.
For the eyes, I found that NOT using an SSS set up for them helps. For example, instead of using the SSS nodes found in the advanced material room for the various sections of the eyes, I used P8 eye settings, and found there is no longer the blue tint on the eyes themselves.
For those brave for the advanced material room, PDG has suggested adjusting the scatter setting on the SSS settings for the eyes and test rendering until a desired effect is gained. As well, specular lighting seems to enhance that blue tint when using IDL lighting. I am going to play with this a bit, as you know me, I am ALWAYS trying to use the RDNA awesome lights LOL
On more lighting tips, there more lights in the scene, the more likely you are to get that blue tint. Another reason I like and recommend the IDL and RPS and GI lights as you can add only the lights you want, and are not stuck loading a pile of lights you don't need. SSS renders trend to give a better result for the skin with a single infinite light, so the fewer the better. If you must use a multiple light set up, then be sure to pull the lights FAR away from the scene to reduce the chance of the blue tint.
I will add more I go ....
Oh on a related note, I asked Colm and he said almost all the light sets from RSP8, IDLs, GI, Rim Lights, Hi Key, all that stuff, will work in P8 and onwards.